Conventional walk behind mulching mowers provide a blade which rotates within an enclosed cutting chamber. Since the cutting chamber or deck is generally completely enclosed, the grass clippings cut by the rotating blade are confined within the chamber and recirculate for being recut by the cutting blade into fine particles or mulch. The finely mulched clippings are then directed down into the turf where they are generally hidden from view and are beneficial as nutrients for the turf grasses. Mulching blades are often utilized which have outer cutting edges for cutting the growing grass and inner mulching edges which recut the grass clippings circulating within the chamber. Walk-behind mulching mowers typically provide a single blade and a single shroud or cutting chamber which surrounds the blade.
Some walk behind mulching mowers provide deflectors which are mounted to the interior walls of the cutting chambers. These deflectors are intended to deflect air and clippings downwardly so that the mulched clippings will be deposited in the turf. Grass clippings can tend to stick or adhere to the deflectors which can create clogging within the chamber. This clogging can slow the flow of materials within the deck, which can increase the horsepower required to drive the blades within the chamber. This clogging can be especially acute when operating the mulching mower in wet conditions.
Wide area mulching mowers typically include a mower deck to which several spindles and blades are mounted. The blades are typically offset from one another so that grass between the blades is mowed completely. Uncut strips of grass between the blades are thereby eliminated. Wide area mulching mowers typically provide each blade with its own shroud for confining clippings to that particular blade. Some conventional mulchers do not properly disperse the mulched clippings into the turf and leave unsightly windrows or clumps of clippings on the lawn. Also, some mulchers act to suspend clippings within the chamber with such force that the clippings are not allowed to drop into the turf, which can clog the cutting chamber and cause poor cut quality. This can also cause large clumps of clippings to fall from the deck when the mower is stopped.
One type of wide area mulching mower provides a pair of cutting blades which rotate in the same direction and in paths which overlap slightly. This type of deck is completely enclosed and does not include a discharge outlet through which clippings can flow. With no discharge outlet to flow through, the clippings tend to wad up within the cutting chambers. Heavy wads of clippings are difficult for the blades to suspend within the chambers, and create resistance to the blades as they rotate within the chambers. This type of mulching mower therefore consumes a large amount of horsepower to drive the blades within the chambers.
Many conventional mulching mowers do not provide enough vacuum effect to lift grass before cutting. This problem is particularly acute in the path of the tire where the contact of the tire against the turf tends to flatten the grass against the ground in front of the mulching deck. Many conventional mulching mowers do not adequately lift the grass that has been flattened by the tire, which results in poor cut quality.
One type of conventional mower that is non-mulching mounts to the belly of a lawn tractor and discharges clippings rearwardly along the centerline of the vehicle. This type of mower deck includes a pair of mower blades which rotate in opposite directions. The blade on the right rotates counterclockwise and the blade on the left rotates clockwise. Grass is cut at the front of the mower deck, and the clippings are then directed to the middle of the deck where they are blown upwardly and to the rear through a discharge outlet formed in the mower deck. A chute then channels these clippings to a bag or container mounted to the rear of the lawn tractor. Many of these mowers provide blades which rotate in paths which overlap. A timing mechanism, such as a toothed belt, is typically utilized for driving the blades so that they do not strike each other within the mower housing where their paths overlap. Since the blade paths overlap, the blades will completely cut the grass between the blades without leaving an uncut strip of grass, and therefore the blades do not have to be offset or staggered in order to cut the grass between the blades. This type of mower positions the blades directly to the side of each other which allows the operator to easily maneuver the vehicle in both directions and facilitates mowing close to objects on either side of the mower and during turns in either direction. By aligning the blades directly to the side of one another the mower deck is relatively compact from front to rear and therefore fits well between the front and rear tires of even small lawn tractors. This type of mower does not mulch grass clippings and therefore requires the operator to dispose of clippings by other means such as bagging.
It would therefore be desirable to provide a wide area mulching mower which effectively cuts grass and mulches clippings even in wet conditions, and which evenly distributes recut clippings into the turf without clumping or windrowing. It would be desirable for such a mower to demand relatively low horsepower from the mower's power source. It would be desirable for such a mower to allow for trimming on either side of the deck and to facilitate maneuverability of the vehicle. It would also be desirable for such a mechanism to be compact for use with relatively small lawn tractors and vehicles. It would be desirable for such a mower to effectively lift grass that has been trampled or flattened by vehicle tires in front of the mower deck so that cut quality is enhanced.